Torwen:
Hello and welcome back to episode 243 of the Ideal Nutrition Podcast. My name is Torwen. And I’m joined today by my co-host Aidan. We are going to be talking about electrolyte supplements. We are giving our thoughts on whether you really need them. Now, this episode is super relevant.
I’m not sure if everyone has seen the electrolyte trends happening at the moment. People wake up and take an electrolyte supplement. And they push it as in this is what you need. So we want to break that down. We want to share our thoughts on whether this is necessary.
Aidan:
So, electrolytes are sodium, potassium, magnesium and calcium. One thing we were debating is how deep we go on each of them. That includes what they are and their role in the body. Obviously, before these podcasts, we do prep. One of the things we wrote down was what they are. And we also wrote down what their role is. It’s just endless. There is that cliché with magnesium. It’s involved in over 300 functions in the body.
So if we were to say what the role is, it would be an endless list. We might do a streamlined version of that. So, I’m going to start with sodium. We might go back and forth. Sodium plays a role in fluid balance. It helps us hold onto water. High sodium pulls water out of the cells. It pulls it into the bloodstream. This is also how it raises blood pressure. It also plays a bunch of other roles. That includes muscle contractions and nutrient absorption.
If levels in the blood get too high, the kidneys excrete more of it. If they get too low, the kidneys conserve more. Antidiuretic hormone regulates water retention. It dilutes sodium if needed as well. One reason why it’s worth talking about the role in the body is the regulation. If things get too high, something happens. If things get too low, something happens. That helps regulate a balance.
Aidan:
Cool. Let’s chat about potassium. Potassium works with sodium to help regulate fluid balance. It also supports muscle contractions, including in the heart. There are many food sources we can get it from. People talk about bananas. And we also talk about potatoes, spinach and kiwi. Some dairy and legumes have it as well. Most people get adequate intake through their diet. However, some people don’t. Adequate intake is close to 2,600 to 3,400 milligrams a day. Some people meet these targets. Yet a lot of people don’t as well.
Aidan:
Yeah, it’s quite a common one that people fall short on. It is interesting because I’m a big proponent of people increasing their potassium intake. It’s hard to make strong arguments for that. I do have one hot take. Increasing potassium intake has more of an effect on reducing blood pressure in those who have high blood pressure.
It seems more impactful than reducing sodium, based on what the research shows. Everyone talks about sodium. Very few people talk about increasing potassium. Magnesium is involved in so many things. Here’s a little fun fact. About 50 to 60% of it is stored in the bones. I think that’s interesting.
It would be a very long list to go through everything. So instead, I’m going to do a short version. It plays a role in energy production. And supports muscle relaxation. It plays a role in nerve function. It helps calm the brain. That’s also how it helps with sleep. It supports bone health because so much is in the bone. It also plays a role in glucose metabolism.
Torwen:
Cool. Calcium is the last one we’re going to talk about. It helps with bone health. And supports muscle contractions. It supports nerve signalling. It supports blood clotting. And it is mainly found in dairy foods. You can also find it in fortified plant milks. Sardines have it too. Anything with little bones has it. Tofu contains calcium as well. Leafy greens also contain it.
Aidan:
Now, when it comes to supplements versus food, it’s worth knowing how much is in each. We’re going to go through one by one again. This suddenly starts getting more interesting. We’re going to talk about sodium. The average person eats an estimated 3,800 milligrams of sodium per day. You could debate that stat. It’s based on self-reported data. I think a good consensus sits around 3,800 milligrams per day. That means nothing in isolation.
It matters once you factor in that most guidelines recommend less than 2,300 milligrams per day. It’s obviously possible to go too low in sodium. Very few people need to worry about it. Athletes can have higher needs. It’s often found in packaged foods. You can literally read the label. And see how much it is.
These numbers now have context. There is also a small amount in natural foods. I’ll chuck in a funny one. In my acute weight cut plans, for people trying to drop weight for competition, I used to recommend low sodium two days out. In my old plans, I used to set a target. I’d say try to have less than 300 milligrams of sodium per day.
That’s super low. Another dietitian on our team said something. Once you factor in natural foods, it’s incredibly difficult to stay below that target. I looked into it. That’s a fair criticism. Now I just say try to avoid as much as you can. Still, a small amount is in natural foods. It’s worth factoring in. Adding salt to food is also a factor. Theoretically, if someone only ate home-cooked food and never added salt, going too low could be an issue.
It seems incredibly rare. So anyway, average intake sits around 3,800 milligrams per day. How much do supplements often add?
Torwen:
It can vary. Let’s take a Gatorade as an example. Let’s just chat sodium. It has 300 milligrams of sodium. A hydrolyte tablet might have 140 milligrams of sodium. Higher electrolyte supplements might have a thousand milligrams of sodium. That’s the same as a My Muscle Chef meal, which is crazy.
Aidan:
I haven’t used it in this one. Yet I do talk about it a bit. Most My Muscle Chef meals are quite high. The first one I picked up was the Chipotle chicken one. It has 1,600 milligrams of sodium. So it’s like, literally just grab this thing. It’s 1,600 milligrams. Even the super high ones like Sodii or Element, the highest I often see in supplements is 1,000 milligrams.
You can have multiple serves if you want to go higher. It is food for thought. Even super high ones are lower than things people naturally consume through food.
Torwen:
Which is crazy. In terms of potassium, should we run through food amounts? We can also cover what we think is adequate.
Aidan:
Absolutely. You already said the goal.
Torwen:
I’ll remind you. It’s 2,600 to 3,400 milligrams a day. If we look at food sources, people always think of bananas. Other food sources include potato. Potato has around 900 milligrams of potassium. Banana has a lot less. It sits between 400 and 500. Avocado contains some potassium as well.
Beans and salmon also contain it. All of those are less than a potato. A single potato has around 900 milligrams.
Aidan:
I’d say potassium comes from all the core food groups. Once you go deep down the rabbit hole, all the core food groups have it. The way to get more potassium is to have more nutrient-rich foods. It also helps to have fewer nutrient-poor foods. You could also link it back to calories. If people have higher calories, they typically get more potassium.
If people have lower calories, they typically get less. That changes if they go out of their way to eat heaps of fruits and vegetables. Typically, electrolyte supplements have 50 to 400 milligrams of potassium. I assume Gatorade falls into that range as well. Very few go much higher. There’s a reason.
High dose potassium supplementation carries risk. It can associate with hyperkalaemia, which is dangerous. Or it can also increase GI issues. Or chronic kidney disease also increases risk. The risk is higher than people think. Once people are above 60, most have some level of chronic kidney disease. So at a population level, it would be risky to go super high-dose potassium in any supplement.
Torwen:
Cool. Magnesium. Let’s chat about it. The RDI of magnesium sits around typical intakes. That’s probably around 300 to 450 milligrams a day. When we talk about supplements, we usually don’t push above 400 milligrams a day from supplements alone. Food sources include nuts and seeds. Whole grains and legumes also contain it. A lot of wholegrain and whole foods are high in magnesium.
Aidan:
And those align with recommended daily intake. A lot of people fall a little short. It’s not massive. Numbers I’ve found suggest around 260 milligrams per day for women. It’s around 320 milligrams per day for men. So they fall just a little under. I use that as an argument for why many people find benefit from supplementing.
You could either get it through food or a supplement. That makes sense. Specific magnesium supplements are often in the 300 milligram-plus range. Standard electrolyte supplements are often low. They often sit around 20 to 100 milligrams.
Torwen:
Calcium, lastly. Calcium sources include dairy and fortified plant-based alternatives. Anything with bones contains it. Tofu contains calcium. Leafy greens contain it. Fortified foods contain it. The RDI for calcium is 1,000 to 1,300 milligrams a day. It depends on life stage and sex. People often fall short unless they consciously ensure enough calcium throughout the day.
Aidan:
Yeah, I saw a number higher than I expected. The average I saw in a report was 850 milligrams. Working with people, I wouldn’t have picked it to be that high.
Torwen:
No, I think in clinic I see a lot less. To give background, a cup of milk is around 300 milligrams. So you’d need around four cups of milk a day. That gets you closer to that level.
Aidan:
It helps more for the higher range. Obviously, many calcium supplements aim for around 1,200 milligrams per day. Calcium is one of those ones where you can only absorb so much in a sitting. So I usually recommend splitting it across the day. Most electrolyte supplements have very little calcium. And that’s because it seems less linked with performance. It also seems less linked with why people use these supplements. Now, another interesting thing is sweat loss during exercise. It relates to sweat rates and testing. Per litre of sweat lost, on average, you lose around 920 milligrams of sodium per hour.
It’s almost a thousand. You lose about 200 milligrams of potassium. 15 milligrams of calcium. And 1.3 milligrams of magnesium. Very little magnesium goes out in sweat. Research shows magnesium levels drop during exercise. Yet it doesn’t seem due to sweat. Those are averages. Individual variation is huge. Some readings go as high as 1,700 milligrams per hour for sodium. Potassium can reach 400 milligrams. Calcium can reach 120 milligrams.
Magnesium can reach 35 milligrams. Note the average magnesium loss is 1.3 milligrams. Even 35 milligrams is a huge difference. Those numbers matter if you try to match losses. Still, you don’t need to match perfectly. You have stores of these things in your body as well.
Torwen:
Recent studies also suggest personalised sweat testing helps quantify losses more accurately. That matters given the massive individual variation. If anyone’s not familiar, a sweat test is simple. You weigh yourself before exercise with no clothes. Ideally, do it after going to the toilet. Then exercise for 60 minutes.
Do it at race intensity in that condition, if possible. Track your fluid intake during the session, if you have any. Then weigh yourself again after, without clothes. The difference in body weight helps work out fluid loss. Then you can quantify electrolyte loss as well.
Aidan:
Absolutely. So when is it worth supplementing? I’ll list some cases. First, it depends on whether you can get it through food. If you’re likely to eat a meal with decent sodium, you might not worry about it. In other cases, that’s less feasible. For example, if someone is fasting in the morning, they may prefer an electrolyte supplement.
A common case is people feeling lightheaded when they stand up. They have sodium. Then they no longer have that issue. So if someone is fasting and dealing with that issue, this could be an easy solution. Another case is exercise. Sometimes it matters during exercise. The My Muscle Chef idea is great. Still, you probably won’t have that in the middle of a marathon. So if someone is a saltier sweater, you can see logic for supplementing. Have you got other ones? We could talk about cramping.
Torwen:
We can talk about cramping. Also, add people getting dizzy if they have something like POTS. Sodium can make a massive difference to those symptoms. So I’d recommend supplementing then.
Aidan:
Do you want to add context? It’s super high. What would you recommend?
Torwen:
It’s super high. Depending on tolerance, you might push sodium up to 3,000. You could go to 7,000 to 8,000 milligrams per day. That’s huge. That’s mostly with very high sodium electrolytes.
Aidan:
Yeah, absolutely. It’s probably the easiest way to do it in many ways. So cramping. We’ve spoken about this before. We know super low electrolytes can cause cramping. We have a lot of evidence on that. One classic example is researchers putting people in hot baths. They made them sweat heaps. Then they only gave them water. They did that until they cramped. Then they gave them salt. They stopped cramping. So we can cause cramping this way.
However, elite athlete cramping seems different. If you go through details, athletes who cramp often have similar electrolyte intake to those who don’t. They also seem to have similar blood levels. Many other variables affect cramping. I would cover your bases. Have some electrolyte intake before and during. For a classic marathon runner, I’d have breakfast with a decent amount of electrolytes. You can add an electrolyte supplement on top. That matters if breakfast is low in electrolytes. Then during, I’d have some as well. A standard recommendation I give is about 500 milligrams of sodium per hour.
Go back to the sweat rate from prior. People often lose close to a thousand milligrams of sodium per litre. Are they sweating a litre per hour? I don’t know. It’s complex. You can measure it too. You don’t need to match perfectly. People have sodium stores. That’s part of why it matters less. I don’t see a downside beyond money. If you want to do it, it makes sense. I’d also have a small amount of potassium. I’d have a small amount of magnesium.
I wouldn’t worry about calcium. Still, I’d have some coming in. It’s hard to make an evidence-based case that this moves the needle in many situations. The clearest situation is sweat testing. That’s when someone turns out to be a higher than average salty sweater. It matters more when they go quite hard. It also matters when they go for over four hours. In that scenario, it makes more sense. The further you get from that, the less likely it matters. Still, you can cover your bases if you want to.
Torwen:
It’s very unlikely that athletes in that scenario won’t replace all fluid losses. So extra electrolytes may help you hold onto more fluid. Sodium also helps reduce urinary output. If you’re doing a long endurance event, does it help that you hold onto more fluid? It might reduce bathroom stops. That is another factor you could consider. But it’s also relevant because more than 2% fluid loss from dehydration can impact performance.
Aidan:
I like that rule of thumb. There’s a niche area, though. I would wager every marathon world record has lost more than 2% of body weight. So there are exceptions. The further you go, like ultra-marathon distance, it matters more. People are less likely to keep going that route. If they keep getting more dehydrated, performance drops more.
So it’s worthwhile keeping the rule in mind. Electrolytes can also help you drink more water. It can happen through two mechanisms. Sodium makes you thirsty. So you want to drink more. Flavouring can also make you drink more. If it makes you go to the bathroom less, that helps too.
Torwen:
When do we not recommend supplements? Should we run through that?
Aidan:
Yeah. Okay. Where do we start? The average office worker who doesn’t exercise much and has a high sodium diet probably shouldn’t use them. High blood pressure is another one. This is complicated because other variables matter for blood pressure more than this. I spoke earlier about potassium having a bigger impact.
Still, I do come across people with high blood pressure taking high sodium supplements. It likely makes their blood pressure worse. Some people argue against that. They point to sodium-mediated hypertension. They say only a certain percentage of people have it. That’s where sodium impacts blood pressure. If you go down that rabbit hole, a huge percentage of people with high blood pressure fit that category. Yet a percentage of people may not.
The only way to find out is trial and error. High sodium one day. Low sodium the next. Repeat it. Then see what happens to blood pressure. Low key, I don’t recommend doing that. If you have high blood pressure, I think it’s borderline unethical to do that test. It’s a risk. So I think it’s not worth adding a tonne of sodium if you have high blood pressure. That’s my two cents.
Torwen:
I think that makes sense. If we look at athletes, context matters. A high sweating endurance athlete may benefit from supplementation. On the other hand, if you do strength training in an air-conditioned gym, you might not need it. That’s especially true if your diet already contains enough sodium.
Aidan:
Cool. Okay, we will wrap up there. This has been episode 243 of the Ideal Nutrition Podcast. If you haven’t already, please leave a rating and review. We massively appreciate that. Apart from that, thank you for listening.